How can I get the same wikipedia page in another language.
For example I want to get this page in Japanese, http://en.wikipedia.org/wiki/Cloud
result is
http://ja.wikipedia.org/wiki/雲 or only the title 雲
Is it possible to use wikipedia API or any other APIs to do this?
prop=langlinks
property of MediaWiki API is probably what you want. Fetching other languages for your cloud example would look like this:
https://en.wikipedia.org/w/api.php?action=query&titles=Cloud&prop=langlinks&lllimit=500&format=json